Source code for linkcheck.loader

# Copyright (C) 2012-2014 Bastian Kleineidam
"""
Functions to load plugin modules.

Example usage::

    modules = loader.get_package_modules('plugins')
    plugins = loader.get_plugins(modules, PluginClass)
"""
import os
import importlib
import pkgutil

from .fileutil import is_writable_by_others


[docs]def check_writable_by_others(filename): """Check if file is writable by others on POSIX systems. On non-POSIX systems the check is ignored.""" if os.name != 'posix': # XXX on non-posix systems other bits are relevant return return is_writable_by_others(filename)
[docs]def get_package_modules(packagename, packagepath): """Find all valid modules in the given package which must be a folder in the same directory as this loader.py module. A valid module has a .py extension, and is importable. @return: all loaded valid modules @rtype: iterator of module """ for mod in pkgutil.iter_modules(packagepath): if not mod.ispkg: try: name = f"..{packagename}.{mod.name}" yield importlib.import_module(name, __name__) except ImportError as msg: print(_("WARN: could not load module %s: %s") % (mod.name, msg))
[docs]def get_folder_modules(folder, parentpackage): """.""" if check_writable_by_others(folder): print("ERROR: refuse to load modules from world writable folder %r" % folder) return for filename in get_importable_files(folder): fullname = os.path.join(folder, filename) modname = parentpackage + "." + filename[:-3] try: spec = importlib.util.spec_from_file_location(modname, fullname) module = importlib.util.module_from_spec(spec) spec.loader.exec_module(module) yield module except ImportError as msg: print(_("WARN: could not load file %s: %s") % (fullname, msg))
[docs]def get_importable_files(folder): """Find all module files in the given folder that end with '.py' and don't start with an underscore. @return: module names @rtype: iterator of string """ for fname in os.listdir(folder): if fname.endswith('.py') and not fname.startswith('_'): fullname = os.path.join(folder, fname) if check_writable_by_others(fullname): print( "ERROR: refuse to load module from world writable file %r" % fullname ) else: yield fname
[docs]def get_plugins(modules, classes): """Find all given (sub-)classes in all modules. @param modules: the modules to search @type modules: iterator of modules @return: found classes @rtype: iterator of class objects """ for module in modules: yield from get_module_plugins(module, classes)
[docs]def get_module_plugins(module, classes): """Return all subclasses of a class in the module. If the module defines __all__, only those entries will be searched, otherwise all objects not starting with '_' will be searched. """ try: names = module.__all__ except AttributeError: names = [x for x in vars(module) if not x.startswith('_')] for name in names: try: obj = getattr(module, name) except AttributeError: continue try: for classobj in classes: if issubclass(obj, classobj): yield obj except TypeError: continue